:root {
  --accent: #4f46e5;
  --accent-dark: #3730a3;
  --accent-light: #eef2ff;
  --text: #0f172a;
  --text-muted: #64748b;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --border: #e2e8f0;
  --success: #059669;
  --radius: 10px;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, .05);
  --shadow-md: 0 4px 12px rgba(15, 23, 42, .08);
  --shadow-lg: 0 20px 40px rgba(15, 23, 42, .12);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", Roboto, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-dark); }

.container { max-width: 1100px; margin: 0 auto; padding: 0 24px; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.nav {
  display: flex; align-items: center; justify-content: space-between;
  padding: 16px 0;
}
.logo {
  display: flex; align-items: center; gap: 8px;
  font-weight: 700; font-size: 1.25rem;
  color: var(--text);
}
.logo-mark {
  width: 32px; height: 32px; border-radius: 8px;
  background: linear-gradient(135deg, var(--accent), #818cf8);
  display: inline-flex; align-items: center; justify-content: center;
  color: white; font-weight: 800; font-size: 0.85rem;
}
.nav-links { display: flex; gap: 32px; list-style: none; }
.nav-links a {
  color: var(--text-muted); font-weight: 500; font-size: 0.95rem;
}
.nav-links a:hover { color: var(--text); }
.nav-cta { display: flex; gap: 12px; align-items: center; }

@media (max-width: 768px) {
  .nav-links { display: none; }
}

/* Buttons */
.btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 10px 18px;
  border-radius: var(--radius);
  font-weight: 600; font-size: 0.95rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all .15s ease;
  text-decoration: none;
}
.btn-primary { background: var(--accent); color: white; }
.btn-primary:hover { background: var(--accent-dark); color: white; }
.btn-ghost { color: var(--text); border-color: var(--border); background: white; }
.btn-ghost:hover { background: var(--bg-alt); color: var(--text); }
.btn-lg { padding: 14px 28px; font-size: 1rem; }

/* Hero */
.hero {
  padding: 80px 0 100px;
  text-align: center;
  background: radial-gradient(ellipse at top, var(--accent-light), transparent 60%);
}
.hero h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 800; letter-spacing: -0.02em;
  line-height: 1.15;
  max-width: 800px; margin: 0 auto 24px;
}
.hero h1 .accent {
  background: linear-gradient(90deg, var(--accent), #818cf8);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero p {
  font-size: 1.2rem; color: var(--text-muted);
  max-width: 600px; margin: 0 auto 36px;
}
.hero-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.hero-note { margin-top: 16px; font-size: 0.9rem; color: var(--text-muted); }

/* Sections */
section { padding: 80px 0; }
.section-head { text-align: center; max-width: 700px; margin: 0 auto 56px; }
.section-head .eyebrow {
  display: inline-block;
  color: var(--accent); font-weight: 600; font-size: 0.85rem;
  text-transform: uppercase; letter-spacing: 0.05em;
  margin-bottom: 12px;
}
.section-head h2 {
  font-size: 2.25rem; font-weight: 800; letter-spacing: -0.01em;
  margin-bottom: 16px;
}
.section-head p { font-size: 1.1rem; color: var(--text-muted); }

/* Feature grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}
.feature-card {
  padding: 28px;
  background: white;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: all .2s ease;
}
.feature-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent);
}
.feature-icon {
  width: 44px; height: 44px;
  background: var(--accent-light); color: var(--accent);
  border-radius: 10px;
  display: inline-flex; align-items: center; justify-content: center;
  margin-bottom: 16px;
  font-size: 1.5rem;
}
.feature-card h3 { font-size: 1.15rem; font-weight: 700; margin-bottom: 8px; }
.feature-card p { color: var(--text-muted); font-size: 0.95rem; }

/* Stats */
.stats {
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 60px 0;
}
.stats-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 32px; text-align: center;
}
.stat-num {
  font-size: 2.5rem; font-weight: 800; color: var(--accent);
  line-height: 1; margin-bottom: 8px;
}
.stat-label { color: var(--text-muted); font-size: 0.95rem; }

/* CTA banner */
.cta-banner {
  background: linear-gradient(135deg, var(--accent), #6366f1);
  color: white;
  padding: 60px 24px;
  border-radius: 16px;
  text-align: center;
  margin: 40px 0;
}
.cta-banner h2 { font-size: 2rem; font-weight: 800; margin-bottom: 12px; }
.cta-banner p { opacity: .9; margin-bottom: 24px; max-width: 500px; margin-left: auto; margin-right: auto; }
.cta-banner .btn-primary { background: white; color: var(--accent); }
.cta-banner .btn-primary:hover { background: var(--bg-alt); }

/* Pricing */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  max-width: 1000px; margin: 0 auto;
}
.price-card {
  padding: 32px;
  background: white;
  border: 1px solid var(--border);
  border-radius: 14px;
  display: flex; flex-direction: column;
}
.price-card.featured {
  border: 2px solid var(--accent);
  position: relative;
  box-shadow: var(--shadow-lg);
  transform: scale(1.03);
}
.price-badge {
  position: absolute; top: -12px; left: 50%; transform: translateX(-50%);
  background: var(--accent); color: white;
  padding: 4px 12px; border-radius: 999px;
  font-size: 0.75rem; font-weight: 700; letter-spacing: 0.05em;
  text-transform: uppercase;
}
.price-tier { font-size: 0.95rem; color: var(--text-muted); font-weight: 600; margin-bottom: 8px; }
.price-amount { font-size: 2.75rem; font-weight: 800; line-height: 1; margin-bottom: 4px; }
.price-amount small { font-size: 1rem; color: var(--text-muted); font-weight: 500; }
.price-desc { color: var(--text-muted); font-size: 0.95rem; margin-bottom: 24px; }
.price-features { list-style: none; margin: 0 0 32px; flex: 1; }
.price-features li {
  padding: 8px 0;
  font-size: 0.95rem;
  color: var(--text);
  display: flex; align-items: flex-start; gap: 10px;
}
.price-features li::before {
  content: "✓";
  color: var(--success); font-weight: 700;
  flex-shrink: 0; margin-top: 1px;
}

/* Content pages */
.content-page {
  max-width: 760px; margin: 0 auto;
  padding: 60px 24px 100px;
}
.content-page h1 {
  font-size: 2.5rem; font-weight: 800; letter-spacing: -0.01em;
  margin-bottom: 8px;
}
.content-page .updated {
  color: var(--text-muted); font-size: 0.9rem; margin-bottom: 40px;
}
.content-page h2 {
  font-size: 1.5rem; font-weight: 700;
  margin: 36px 0 12px;
}
.content-page h3 {
  font-size: 1.15rem; font-weight: 700;
  margin: 24px 0 8px;
}
.content-page p { margin-bottom: 16px; color: #334155; }
.content-page ul, .content-page ol { padding-left: 24px; margin-bottom: 16px; }
.content-page li { margin-bottom: 6px; color: #334155; }
.content-page table {
  width: 100%; border-collapse: collapse;
  margin: 16px 0;
}
.content-page th, .content-page td {
  border: 1px solid var(--border);
  padding: 10px 14px;
  text-align: left;
  font-size: 0.95rem;
}
.content-page th { background: var(--bg-alt); font-weight: 600; }

/* Contact */
.contact-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
  margin: 40px 0;
}
.contact-card {
  padding: 24px;
  background: var(--bg-alt);
  border-radius: var(--radius);
  border: 1px solid var(--border);
}
.contact-card h3 { font-size: 1rem; font-weight: 700; margin-bottom: 8px; }
.contact-card p { color: var(--text-muted); font-size: 0.95rem; margin-bottom: 0; }
.contact-card a { color: var(--accent); font-weight: 500; }

/* Footer */
.site-footer {
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  padding: 60px 0 30px;
  margin-top: 80px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: 40px;
  margin-bottom: 40px;
}
@media (max-width: 720px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
.footer-col h4 {
  font-size: 0.85rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.05em;
  color: var(--text-muted);
  margin-bottom: 16px;
}
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 8px; }
.footer-col a { color: var(--text); font-size: 0.95rem; }
.footer-col a:hover { color: var(--accent); }
.footer-tagline { color: var(--text-muted); font-size: 0.95rem; margin-top: 12px; max-width: 280px; }
.footer-bottom {
  padding-top: 24px; border-top: 1px solid var(--border);
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px;
  font-size: 0.85rem; color: var(--text-muted);
}

/* Language switcher */
.lang-switch {
  display: inline-flex;
  align-items: center;
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 2px;
  background: white;
  margin-right: 8px;
}
.lang-switch a {
  padding: 4px 12px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  border-radius: 999px;
  transition: all .15s ease;
}
.lang-switch a.active {
  background: var(--accent);
  color: white;
}
.lang-switch a:not(.active):hover { color: var(--text); }
@media (max-width: 768px) {
  .lang-switch { margin-right: 4px; }
}